The Sensitivity of Halo Nuclei to the Nuclear Radius

β-decay provides important information about the structure of halo nuclei. Because of the root-mean-square radius (Rrms) of the neutron halo distribution is very large, the phase-space factor for halo nuclei must be more sensitively depended on the radius. In this work the sensitivity of the nuclear radius to the phase-space factor was investigated for some halo nuclei and the improvement for phas-space factor for halo nuclei was reported. The results wrere applied to calculate the logft-values for the halo nuclei(6He, 8He, 11Be, 14Be, 9Li, 11Li). The modification proposed shows reasonable results for many casesn/a